Immunoselection of oligodendrocytes by magnetic beads. II. In vitro maintenance of immunoselected oligodendrocytes.

Oligodendrocytes isolated by immunoaffinity on magnetic beads using a monoclonal antibody to oligodendrocyte cell surfaces were obtained with a purity of 91 +/- 4% [see companion paper, Meier et al, 1982]. Contaminating cells consisted mostly of tetanus toxin-positive neurons with small cell bodies. Very few glial fibrillary acidic protein-positive astrocytes and fibronectin-positive fibroblasts or fibroblast-like cells could be detected by indirect immunofluorescence. Macrophages, as identified by their characteristic morphology, were rarely detectable in the cultures. With increasing time in culture, the degree of homogeneity of the cultured oligodendrocytes increased slightly, while the cell density of oligodendrocytes decreased drastically within the first week of culture. Cultures of immunoselected oligodendrocytes with a lower degree of purity showed a better survival of oligodendrocytes, but a considerable reduction in purity after three weeks in culture, probably due to overgrowth of nonoligodendroglial elements.